After praising those who try to make the world a more peaceful place, former assistant secretary general of the United Nations Dr. Robert Muller began to play Beethoven’s “Ode to Joy” on his harmonica while an audience of about 50 people applauded.

The 81-year-old Muller gave a lecture at Embarcadero Hall on Tuesday night for a fundraiser for the Model U.N. Club. Muller, who worked for the United Nations for nearly 38 years, used his time to briefly discuss his book, 6,000 Ideas for a Better World, and to talk to the audience about the importance of working for world peace. He is currently Chancellor Emeritus at the University for Peace, created by the U.N. in Costa Rica.

Muller presented his audience with a message of hope for a peaceful future, a message that he would reiterate many times during the course of the speech.

“There is something going on on this planet,” Muller said. “There are invisible forces that want this world to succeed, and we are going to succeed in it.”

Muller related an experience from when he was a member of the French resistance to the Germans in World War II. Peasants alerted Muller’s unit to 20 German soldiers hiding in a farmhouse. Muller said he assured the Germans over a loudspeaker that they would be safe if they surrendered. He later learned that his commander had the Germans shot because they were proud when they were led past a place where French villagers had been burned alive by the German army.

Muller said the experience convinced him that it was his destiny to commit his life to working for peace. Author Douglas Gillies, who recently published a biography on Muller, called him a prophet because of his long career as a committed peacemaker.

“It seems like boasting to call someone a prophet,” Gillies said. “Frankly, I think a great many of us don’t think there’s much of a future. Robert Muller, in his years in the United Nations, developed an ability to see the future and then to come up with programs that would make the future work better, and he created them over and over again.”

Ellie Kledanow, vice president of the Model U.N. Club and sophomore international relations major, said the club promotes conflict resolution and tries to educate people about global issues. She said she considered Muller an inspiration.

“He came from a point in his life where he really didn’t think it was possible to make a difference and ended up making a huge difference,” Kledanow said.

Ten countries will be joining the U.N. in May, and 25 more have applied for membership, Muller said. He said he is excited about the organization’s growth, and at age 81 he feels better than ever and plans to continue his career as a peacemaker.

“I am younger than ever. I am more prolific than ever. The doctor whom I saw the other day said I have the health of a 20-year-old,” Muller said.